خازن گذاري بهينه در سيستم توزيع نامتعادل و در حضور بارهاي هارمونيكي

چكيده انگليسي :

Optimal Capacitor Placement in Unbalanced Distribution System in Presence of Nonlinear Loads Seyed Rasoul Hosseini Sr hosseini@ec iut ac ir Date of Submission 2010 04 20 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Mohammad Esmaeil Hamedani Golshan hgolshan@cc iut ac irAbstract Expert and managers have been interested in loss problem for a long time From the beginning ofelectricity systems expansion there have always been efforts to reduce the power losses However theamount of power losses is still high and there is always a considerable amount of loss in different parts ofpower system such as transmission and distribution lines and transformers present in annually reports These reports represent the amount of attention and work the power system and distribution officials doregarding this issue With further development and expansion of the power systems and shortage of thealready running out natural fuels efficient use of the power produced in the power plants is one of the mostimportant issues at hand There have been efforts to counter this issue such as increasing the amplitude ofthe line voltages in case of large power transmission in long distances But increasing the voltage level hasits own drawbacks of requiring higher isolation which makes it problematic to be used in distributionnetworks The introduction of the reactive power consumption made the power engineers wonder thatalthough the losses caused by power transmission can be decreased by increasing the conductors crosssection has little economical justification It is possible to reduce the amount of reactive power by usingcompensators so that the losses caused by reactive power transmission can be eliminated Loss indistribution networks according to many reasons are the dominate part of power system losses So lossanalysis and finding ways to reduce it became important Optimal capacitor placement has an important rolein power systems planning and operation Installing shunt capacitors in distribution system specifically forloss reduction improving voltage profile in feeders power factor correction and releasing feeder capacity is known subject in effective operation of distribution systems Of course do to not considering some of theoperational limits such as unbalance system and nonlinear loads by using shunt capacitors in distributionsystems the network loss may be significant Unbalanced three phase lines unbalanced loading andpresence of single and two phase lines caused unbalanced conditions in distribution system Vast nonlinearloads and power electronics elements usage lead to harmonic current production and injection to powersystem Capacitor placement in distribution system including location type and optimal size determinationis so to minimized losses and capacitor cost simultaneously In large scale systems solution of this problemis dependent of computer speed because of increasing bus numbers and system size So presenting analgorithm which is capable to solve this problem in sufficient time and by acceptable accuracy is one of themain parts of this process Among of existence methods for optimization problems artificial intelligenceand heuristic methods are good candidates In this thesis capacitor placement problem in unbalanceddistribution networks in presence of harmonics as an optimization problem by discrete variables has beenstudied and economical parameters such as inflation and interest rate for an accurate economical assessmentare considered We used binary Particle Swarm Optimization algorithm Different formulation of capacitorplacement on several balanced and unbalanced test systems are simulated and analyzed Keywords Capacitor Placement Unbalanced Distribution System Nonlinear Load PSO Algorithm

حسيني، رسول

خازن گذاري بهينه در سيستم توزيع نامتعادل و در حضور بارهاي هارمونيكي

بار غير خطي , الگوريتم PSO